Use of prophylactic antibiotics in orthopedic surgery.

The use of prophylactic antibiotics was studied prospectively in 2371 consecutive clean orthopedic operations. The infection rates for operations with obvious selection for antibiotic prophylaxis were twice as high (7.2%) as compared with operations with planned prophylaxis (3.4%) and with operations without such prophylaxis (3.7%). Sixteen per cent of all clean operations received antibiotics for prophylaxis and 85 per cent of all prophylactic courses lasted at least 8 days or longer. Fifty-one per cent of all antimicrobial drugs used during the study were administered for prophylaxis in clean orthopaedic operations. The length of the hospital stay was the only factor closely related to the length of antibiotic prophylaxis. The drugs most often used for prophylaxis were penicillinase-resistent penicillins. Significant increase of gram-negative pathogens was observed in cultures from wounds of patients on antibiotic prophylaxis.